Interesting post today on the Facebook developer blog regarding the roadmap. The post noted that, among other things:
Finally, due to low usage rates, we will remove application tabs from user profiles in the next couple months. Application tabs will continue to be supported on Facebook Pages.
Good thing I finally got around to updating WPBook to support FBML-based tabs, just in time for them to be discontinued. ;)
Oh well, once they allow iFrames on tabs we’ll get the ability to do things like embedded videos. But then they’ll take tabs away from individual profiles? So individual profiles won’t have boxes or tabs?
I guess that will just encourage anyone really using WordPress as a platform for promoting their blog will end up creating a page, and then using the tab in the page?
You can see a timeline of some of the updates here: Developer Roadmap
They also changed the developer app again:
We’ve also spent some time cleaning up some of our developer tools and documentation. We’ve simplified the Developer application by removing obsolete settings and tabs
So the instructions for WPBook which I just updated last weekend will need updating again to match the new settings look & feel. Ah the joys of depending on a third party platform . . .